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Reference documentation for deal.II version 9.6.0
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#include <deal.II/lac/trilinos_precondition.h>
Public Member Functions | |
AdditionalData (const double omega=1, const double min_diagonal=0, const unsigned int overlap=0, const unsigned int n_sweeps=1) | |
Public Attributes | |
double | omega |
double | min_diagonal |
unsigned int | overlap |
unsigned int | n_sweeps |
Standardized data struct to pipe additional flags to the preconditioner. The parameter omega
specifies the relaxation parameter in the SSOR preconditioner. The parameter min_diagonal
can be used to make the application of the preconditioner also possible when some diagonal elements are zero. In a default application this would mean that we divide by zero, so by setting the parameter min_diagonal
to a small nonzero value the SOR will work on a matrix that is not too far away from the one we want to treat. Finally, overlap
governs the overlap of the partitions when the preconditioner runs in parallel, forming a so-called additive Schwarz preconditioner.
Definition at line 344 of file trilinos_precondition.h.
TrilinosWrappers::PreconditionSSOR::AdditionalData::AdditionalData | ( | const double | omega = 1, |
const double | min_diagonal = 0, | ||
const unsigned int | overlap = 0, | ||
const unsigned int | n_sweeps = 1 ) |
Constructor. By default, set the damping parameter to one, we do not modify the diagonal, and there is no overlap (i.e. in parallel, we run a BlockJacobi preconditioner, where each block is inverted approximately by an SSOR).
Definition at line 129 of file trilinos_precondition.cc.
double TrilinosWrappers::PreconditionSSOR::AdditionalData::omega |
This specifies the (over-) relaxation parameter in the SSOR preconditioner.
Definition at line 361 of file trilinos_precondition.h.
double TrilinosWrappers::PreconditionSSOR::AdditionalData::min_diagonal |
This specifies the minimum value the diagonal elements should have. This might be necessary when the SSOR preconditioner is used on matrices with zero diagonal elements. In that case, a straight-forward application would not be possible since we divide by the diagonal element.
Definition at line 370 of file trilinos_precondition.h.
unsigned int TrilinosWrappers::PreconditionSSOR::AdditionalData::overlap |
This determines how large the overlap of the local matrix portions on each processor in a parallel application should be.
Definition at line 376 of file trilinos_precondition.h.
unsigned int TrilinosWrappers::PreconditionSSOR::AdditionalData::n_sweeps |
Sets how many times the given operation should be applied during the vmult() operation.
Definition at line 382 of file trilinos_precondition.h.